Naturally occurring vinca alkaloids, vincristine and vinblastine, at micromolar concentrations enhanced the ornithine decarboxylase activity in a dose-response manner in primary cultures of Ehrlich ascites carcinoma cells. After 8 h of culture in the presence or absence of vinblastine, cycloheximide was added to the medium, a 4.5-fold increase in the half-life of the ornithine decarboxylase act...

Sir: In our screening programme for an antitumor agent using the mouse Ehrlich ascites tumor, it was found that fatty acids extracted from some fungal mycelia showed significant antitumor activity in vivo. In primary screening, the acetone extracts of the mycelia of Penicillium crustosum IAM 7014, Pen. tardum IAM 7206, Caphalosporium diospyri and Sepedonium ampullosporum showed antitumor activi...

The carcinostatic activity of elatericin A, elatericin B, elaterin, elaterin methylether, dihydroelatericin A, and tetrahydroelatericin A, all cucurbitacins of a triterpene structure, and of trans-4-hydroxy-4-methylpent-~-enoic acid, the isolated side chain of the cucurbitacin molecule, was studied. Three cucurbitacins, elatericin A, elatericin B, and elaterin produced a moderate inhibition of ...

Five analogs of Tilorone hydrochloride demonstrated varying degrees of activity on the following host defense mechanisms: (a) antitumor activity to Ehrlich carcinoma solid tumor and Friend leukemia virus, (b) in vivo antibacterial activity to Staphylococcus aureus, (c) functional activity of the reticuloendothelial system, and (if) enhancement of the 19 S immunological response. Bis(3-diethylam...